This invention relates generally to a new and improved apparatus and method for accumulating fuel particles in a portion of a combustion chamber through the use of a plurality of electrostatic fields.
A method and apparatus utilizing electrostatic fields and corona discharges to attract fuel particles to a portion of an engine combustion chamber is disclosed in U.S. Pat. No. 4,041,922. The apparatus disclosed in this patent is utilized to establish a corona discharge at a single electrode gap which is exposed to the atmosphere in the combustion chamber. During an engine operating cycle, the atmospheric conditions in the combustion chamber vary in such a manner that the corona discharge can only be established during the compression stroke.
Another apparatus for electrostatically attracting fuel particles to a portion of a combustion chamber is disclosed in U.S. patent application Ser. No. 732,971 filed Oct. 15, 1976 and entitled "Ignition Method and Apparatus for Internal Combustion Engine" now U.S. Pat. No. 4,124,003. Although this application discloses several different ignition devices and methods, one of the ignition devices disclosed in the application utilizes a main spark plug and a secondary spark plug. A corona discharge is established at the secondary spark plug to effect the attraction of fuel particles to a portion of the combustion chamber adjacent to the main spark plug. The main spark plug effects initial ignition of the air-fuel mixture. Thereafter the corona discharge at the secondary spark plug changes to a continuous spark discharge to positively fire the air-fuel mixture. Still another known device utilizing a corona discharge in association with a spark plug is disclosed in U.S. Pat. No. 3,974,412.
In addition to the devices set forth above, there are many other devices for igniting a charge in a combustion chamber. One of these devices is disclosed in U.S. Pat. No. 3,842,819. This device includes a main electrode having a series gap which is wider than the associated sparking gap. The purpose of the relatively wide series gap in the main electrode is to break down and cause a rapid rise in the voltage at the spark gap. A somewhat similar ignition device is also disclosed in U.S. Pat. No. 3,842,818. It should be noted that in both of these patents the series gap in the main electrode is disposed outside of the combustion chamber and an electrostatic field at this gap would be ineffective to influence the fuel particles in the combustion chamber. In addition, spark plugs having a plurality of electrode gaps are disclosed in U.S. Pat. Nos. 2,071,254; 3,488,556; and 3,577,170.